so I just got off the phone from Rob at Auto Gas Injection in frankston.
his advice is that unless im planning on chasing big horsepower by changing cams, doing head work etc etc that its best to just fit a vapour system - they use an emer system. his price for that was $3950 before rebate..
he indicated that the system will be fine with an exhaust - either cat back or full system with extractors - and OTR mods at WOT - no leaning out or switching back to petrol etc.
after getting of the phone I then googled emer vapour injection and read a few things (nothing decisive) but then ended up on the Autralian LPG Warehouse site and from there rang 1300 574 669 to seek more advice and opinions!
I spoke to a Michael who I have to say was fantastic. gave what appeared to be very open and honest feedback on both vapour and liquid systems with bagging brands from alternate suppliers. they handle both the emer vapour which he described as the "series 2 upgrade" of the eurogas system as well as the JTG liquid system.
in summery:
* Vapour (emer):
- 15-25% more usage than running on petrol (advised that lots of variables can effect where in that range it falls)
- no performance loss (no increase either!)
- 61 litre tank
- can handle mods to the exhaust and intake (natural not forced)
- quickest vapour injectors on the market
- "uglier" under the bonnet
- 3 year warranty
* Liquid (JTG);
- 10-20% more usage than running on petrol (again variables effect that) (5% better economy than vapour)
- even with the vehicle in stock standard trim you could expect to see kw gains - he did however say whilst it would show on the dyno it probably wouldnt be noticable on the road
- approx 50 litre tank - tank is the same size but it has a pump in it and must keep 4 lires in it for the pump
- can handle what ever mods you like and is well suited to super charging or turbo charging.
- neater under the bonnet
- 3 year warranty
- as it has no computer of its own it can be worked on by just about any competent workshop around the country - if they arent familiar with it phone support can advise them of what/where to check etc
in short he said either system would be fine, but as I am planning on holding it for 5+ years if I can stretch the extra dollars that he would recommend it as it will enable future mods if I feel that way inclined but also as the system offers slightly better economy than the vapour system the extra upfront will also pay itself back over time in further savings.
based on all of the above I know just need to decide on an installer and I'm 99% i'll go with the Liquid system. One of my thoughts here is that when I do sell in 5+ years time theres every likely hood that potential purchasers would be wanting go to town on the engine so having a system already fitted that can handle it will be a better sell than them then having to change the fitted system?? (i'll be using that logic on the mrs anyway!!)
I've spent countless hours over thae past week googling, reading, speaking to people etc and wish I had earlier got on to michael at the number above - he was extremly helpful, seemed very knowledgable and was happy to answer what ever question I threw at him (even the ones I was almost embarressed to ask for fear of it being a stupidly obvious thing!!) - If you're reading this at any point going through the same process I have in the past week I can strongly recommend you call 1300 574 669
*disclaimer: I have absolutly no affiliation what so ever to any mechainical business mentioned in any of my posts!
cheers